Usage: just swipe the screen to begin setting the alarm, tap until you have set the appropriate time, then swipe back to the clock view. An alarm clock icon will show, and some time later, Bob will appear and begin heckling you.
Like all third party alarm clocks, the app needs to be left running overnight to work! This is works fine if you leave it running on your nightstand as the device recharges. The current time will be displayed, and Bob will occasionally pop into view as he waits for his alloted time to approach.
Oh, and be careful not to leave your device muted. That can rather defeat the usefulness of an alarm clock.